1. Technical Field
The present invention relates to a printer platen support mechanism that can move a platen.
2. Related Art
When loading roll paper in a roll paper printer, the cover of the roll paper printer's roll paper compartment is opened, the roll paper loaded, and a recording paper web is pulled from the roll and threaded through a recording paper transportation path past the printing position of a print head. To simplify this task, a platen support mechanism may be configured so that a platen moves away from the printing position (from the print head disposed on the printer case side) and opens the recording paper transportation path when the cover of the roll paper compartment opens.
For example, Japanese Unexamined Patent Appl. Pub. JP-A-2001-158142, which corresponds to U.S. Pat. No. 6,474,883, teaches a platen support mechanism (cover opening and closing mechanism) that, for example, supports a platen unit to which the platen is disposed by means of a four joint parallel linkage mechanism, and moves the platen unit located directly above the roll paper compartment with the cover along an arcuate path to the front of the printer while holding the platen unit horizontal.
The platen unit also descends as front and back links that support the platen unit move forward with the platen support mechanism using a four joint parallel linkage mechanism. Sufficient space must therefore be opened below the platen unit (between the platen unit and roll paper) so that a bottom end of the platen unit does not interfere with the roll paper loaded in the roll paper compartment.
More specifically, when roll paper with the largest diameter compatible with the roll paper printer is loaded, sufficient space must be opened between the roll paper and the platen unit. While this space is needed for the platen unit to move, the height of the roll paper printer can be reduced and the printer size can be reduced if this space is reduced or eliminated.